Dear Debbie,
I took out my catheter the morning after my TURB as instructed. Felt reasonably OK all day, although I'm sure the Detrol helped with the bladder spasms. By evening my stream was becoming weak. By the middle of the night I couldn't urinate, so I drove to the ER and was sent home catheterized. Once again, as instructed, I removed my catheter the next morning, and by the next night was again obstructed, so back to the ER. This time the catheter stayed a few days until I saw my urologist (and found out my diagnosis).
He gave me a few catheters and instructed me in self catheterization. The following week, a large clot came partially off the bladder wall and obstructed my flow. I tried the catheter, but the clot obstructed the catheter. Fortunately, on removal of the catheter I experienced a gush of urine that provided much relief, although I was up all night until the clot finally broke free and passed. So yes, even catheters don't guarantee free flow of urine.